The present invention relates to a method for identifying one or more objects, comprising the following steps: generating a two-dimensional, optically readable pattern and an identification code, the pattern and the identification code being paired in one-to-one correspondence by means of a predetermined algorithm; providing a two-dimensional representation of the pattern on the or each object, or on a pattern support to be connected to the or each object, such as a label, sticker or the like; storing the identification code and associated identification information; optical scanning of the representation of the pattern of the or each object; determining the associated identification code; and identifying the or each object on the basis of the identification information associated with the identification code.
The invention also relates to a system for implementing the method.
In the prior art, such a method is known for identifying an object by means of a barcode or a dotcode, in which the code in the form of regular, machine-readable pattern of bars or dots, respectively, can have been provided directly on a surface of the object or can also have been provided on a support affixed to the object. The barcode and the dotcode are structured for many applications according to internationally accepted standards, each represent an alphanumeric identification code and are often issued centrally to prevent one and the same code being used for the identification of different objects.
The barcode is a one-dimensional code which has a limited length and hence offers a limited number of mutually different identification codes. The dotcode is a two-dimensional code which, per unit of surface, offers a greater, but still essentially limited number of mutually different identification codes. A drawback with using a barcode and a dotcode is consequently that, because of the quantity of identification codes thereby to be formed, which quantity is limited within reasonable dimensions, they are unsuitable for mutually differently characterizing large quantities of objects on which the surface for the application of the barcode or dotcode is relatively small.
Another drawback is that one is generally dependent upon an external body for the issuing of a new barcode or dotcode, in which case there will be a considerable, in many cases unacceptable time delay and some desired codes may turn out to be unavailable.
From document U.S. Pat. No. 5,354,097, it is known per se to use a unique pattern of overlying individual fibres embedded in a transparent material, for demonstrating the authenticity of an object by making use of the unique three-dimensional characteristics of a fibre pattern of this kind through optical scanning from one or more different directions. From the aforementioned document it is not known to use the fibre pattern embedded in a transparent material as a means for identifying objects.
Moreover, the stiffness needed for the required dimensional stability would render the fibre pattern embedded in a transparent material unusable for many applications, for example the identification of flexible objects such as textiles. In addition, an optical scanning of the fibre pattern, especially in the case of flexible objects, is particularly awkward to conduct, since under these circumstances the fibre pattern could only be reliably positioned relative to an optical scanning device with great difficulty. Owing to the required depth of field, furthermore, the fibre pattern can only be scanned at a relatively short distance.
The invention aims to overcome the aforementioned drawbacks, or at least largely eliminate them, and to this end firstly provides a method of the kind stated in the preamble, which is characterized in that the pattern is arbitrary. By giving the pattern a perfectly arbitrary shape in a suitable manner and by deriving, on the basis of the obtained shape, a, for example, alphanumeric identification code by means of a predetermined algorithm, the pattern and the identification code being paired in one-to-one correspondence, it becomes possible to identify objects without the need for outsourcing, using a pattern provided thereon or connected thereto, with a practically negligible chance of a like pattern or a like identification code being generated elsewhere.
Of course, it is not necessary to start off from an arbitrary two-dimensional pattern and to derive an identification code from this by means of an algorithm. An arbitrary identification code can also form the starting point, an algorithm being used to generate a two-dimensional pattern. The only points of importance are that the two-dimensional pattern or the identification code are completely arbitrary and that there is a one-to-one correspondence between them.
The identification code can be stored in a file and can be coupled with associated identification information, such as data relating to the producer of the object and/or the owner thereof, and any other relevant information. A two-dimensional representation of the generated pattern is provided on the object to be identified, or on a pattern support to be attached thereto. In identifying the object, the two-dimensional representation of the pattern is optically scanned, on the basis of which the associated identification code is determined. The identification code gives access, in turn, to the identification information which is coupled thereto.
Given a suitable choice of the arbitrary two-dimensional pattern, the two-dimensional representation can be particularly small, more particularly considerably smaller than the usual barcodes and dotcodes, yet still has the same possible quantity of different identification codes. The two-dimensional representation will nevertheless be easy to read from a relatively large distance (in the order of a few metres) using a camera.
In a preferred embodiment of the method according to the invention, the step of generating the arbitrary two-dimensional pattern comprises the step of optically scanning one or more irregularly arranged bodies having an arbitrary three-dimensional shape, especially the optical scanning of a number of arbitrarily arranged individual fibres from a predetermined direction.
Fibres of this type can form part, for example, of an authenticity mark as described in U.S. Pat. No. 5,354,097, and the two-dimensional representation derived from the authenticity mark of an object, document or the like can be provided on one or more other objects, documents or the like which have to be identifiable as belonging with the object, document or the like being provided with the authenticity mark.
Further preferred embodiments of the invention are described in the subclaims.
According to the invention, a system for identifying one or more objects comprises: means for generating an arbitrary, two-dimensional, optically readable pattern and an identification code, the pattern and the identification code being paired in one-to-one correspondence by means of a predetermined algorithm; means for providing a two-dimensional representation of the pattern on the or each object, or on a label to be connected to the or each object; means for storing the identification code and associated identification information; means for optically scanning the representation of the pattern of the or each object; means for determining the associated identification code; and means for identifying the or each object on the basis of the identification information associated with the identification code.
Preferred embodiments of the system according to the invention are described in the sub-claims.